Brain injuries most likely due to his football career were among the contributing causes in the death of Chuck Osborne, the Canyon High School football standout who went on to a four-year career with the National Football League.

On Oct. 16, 2012, Osborne, age 38, was found dead in the bedroom of a La Jolla apartment he shared with a roommate.

In lay terms, that translates to “disease of the heart muscle, usually due to high blood pressure which, in his case, is related to obesity and hypertensive high blood pressure,” said Lauren Fisher, an investigator with the San Diego County Medical Examiner’s Office.

Osborne weighed 326 pounds on the day of his death. He stood 6 feet 2 inches tall.

But the former defensive tackle also suffered “traumatic encephalopathy,” which Fisher explained as “brain injury probably due to his football career.”

He took powerful drugs prescribed to him over the years for pain — chronic pain suffered during four years in the National Football League and after — that also contributed to his death, causing breakdown in his organs including his brain, Fisher said.

Parts of Osborne’s brain and spinal cord were sent to the Center for the Study of Traumatic Encephalopathy Neuropathology at Boston University. There Dr. Ann C. McKee, a co-director at the center, diagnosed Osborne as suffering from chronic traumatic encephalopathy, or CTE.

PLAYER INJURIESOsborne played defense for the Canyon High School Cowboys and for the University of Arizona Wildcats before his career in the NFL.

He was a two-time All-Golden League selection for the Cowboys and was rated the No. 4 defensive lineman in the country in 1991.

As part of Arizona’s “swarm defense” he set a team record of 11 sacks in 1994, closing out his college career with 21 sacks.

After college, he was selected by the St. Louis Rams during the seventh round of the 1996 NFL Draft. He appeared in 37 regular-season NFL games, spending two years with the Oakland Raiders before signing with the Green Bay Packers and later with the New England Patriots.

His diagnosis of CTE puts him in the company of Tony Dorsett, one of the greatest running backs of all time, and former Miami Dolpins All-Pro wide receiver Mark Duper.

Symptoms for CTE include depression, mood swings, memory loss and eventually dementia. Dorsett told ABC News he gets lost sometimes just driving his daughters to soccer games.

In the last few years, the NFL has wrestled with the issue of players suffering brain damage due to “repetitive concussive and subconcussive brain trauma.” In August, according to the Associated Press, the league reached a tentative $765 million settlement over concussion-related brain injuries among its 18,000 retired players, agreeing to compensate victims, pay for medical exams and underwrite research.

In September, Osborne’s name was added to the list of NFL players diagnosed with CTE, according to McKee’s final report sent to the San Diego Medical Examiner Sept. 11.

Friends and family members, however, who watched the mind and body of a bright young football star deteriorate into a man racked with intense chronic pain, described Osborne’s condition as anything but “mild.”

“He had been a nose guard in the NFL and his mother (Kathleen Bajgrowicz) said that he sustained multiple concussions. His mother reported that in 1998 or 1999 he lost consciousness while at dinner with football teammates,” Mena wrote.

About six months prior to his death, Osborne nearly blacked out while driving. Emergency room doctors issued a “presumptive diagnosis of seizures.”

Nine days later the same thing happened behind the wheel. Osborne pulled over and passed out, according to the autopsy report. At the hospital, he told doctors of two prior blackouts. He said he found himself on the ground after each episode, unable to recall how he got there.

DEPRESSIONOsborne also suffered from depression. When Fisher compiled her Medical Examiner report she noted: “The decedent had been depressed and having feelings of guilt over the recent death of his wife.”

Osborne’s wife, Heather, died accidentally Jan. 4, 2012. Her cause of death was listed as “acute combined cocaine, ethanol, heroin toxicity,” said Terrel Harris, spokesman for the Boston Medical Examiner.

Still, Osborne’s roommate, James Charlesworth, told Fisher: “He never made any suicidal threats or ideations and had actually stated that he was ‘scared to die.’”

Charlesworth found Osborne dead on the afternoon of Oct. 16, 2012, inside the apartment they shared on Villa La Jolla Drive in La Jolla.

The night before he died, the two roommates had watched some TV together, Fisher wrote. Charlesworth told her Osborne was incoherent, had slurred speech and had taken some pain killers.

Investigators found his bedroom to be minimally furnished with a box spring and mattress on the floor and little else. But in the room was a box containing “numerous over-the-counter prescription medication bottles located on top of a cabinet.” There were “no illicit drugs, alcoholic beverages, weapons or suicide notes.”Toxicologists found trace amounts of drugs for pain and anxiety in his system.